Arterial blood gases or ABG’s are used to measure the level of acidity and level of oxygen and carbon dioxide in the blood through an artery. Blood is taken from an artery instead of through a vein to accurately test how well the lungs are moving the oxygen into the blood and removing the carbon dioxide from the blood. It measures the oxygen and carbon dioxide levels before they enter the body tissues. There are several reasons why an ABG must be done:
1) To check for severe breathing problems or lung diseases, such as asthma & COPD.
2) To see how well the treatments for lung diseases is working.
3) To find out if you may need help with breathing.
4) To find out if you are receiving the right amount of oxygen while in the hospital.
5) To measure the acid base level in the blood for patients who have heart failure, kidney failure, uncontrollable diabetes, sleep disorders, severe infections, or after a drug overdose.
What is measured? What does it indicate?
An ABG test measures the PaO2, PaCO2, pH, & HCO3 levels.
The PaO2 also called the partial pressure of oxygen measures the pressure of oxygen dissolved in the blood and how well the oxygen is able to move from the airspace of the lungs into the blood.
The PaCO2 also called the partial pressure of carbon dioxide measures how much carbon dioxide is dissolved in the blood and how well the carbon dioxide can move out of the body.
The pH measures the amount of hydrogen ions in the blood.
The HCO3 also called the bicarbonate is a chemical buffer that keeps the pH of the blood from becoming too acidic or too alkaline.
What is normal?
The normal ranges for ABG testing is as follows:
PaO2 80-100
PaCO2 35-45 pH 7.35-7.45
HCO3 22-26
What do abnormal results indicate?
When evaluating the ABG test results follow these simple steps to determine whether
